Ethereum has externally owned accounts, controlled through private keys, and contract accounts, controlled by deployed code. Both can hold assets and interact with smart contracts.
Externally owned accounts initiate transactions
An EOA uses a key pair to sign transactions and has a nonce that helps prevent replay. A wallet is the interface used to manage that account; the wallet and account are not the same thing.
An account is not the wallet application
A wallet helps manage keys and submit requests, while the account and its state exist on Ethereum. Switching wallet software does not create a new blockchain account if the same keys are used.
Contract accounts follow programmed logic
A contract account has code and storage instead of a private key. It acts when called, and its permissions may support multiple signers, spending rules, recovery logic, or application-specific behavior.
Contract accounts can encode custom authority
Instead of one private key directly controlling every action, contract logic can require thresholds, time delays, modules, or other conditions.
Sources
Educational information, not investment advice.